#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
int main()
{
	int n = 0;
	int sum = 0;
	int ret = 1;
	for (int n = 1;n <= 3;n++)
	{
		for (int i = 1;i <= n;i++)
		{
			ret *= i;
	   }
		sum += ret;
	}
	printf("%d\n", sum);
	return 0;
}